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United States Patent | 5,025,239 |
Murashima ,   et al. | June 18, 1991 |
An electromagnetic actuator suitable for use in combination with the mechanisms of cameras and the like. The electromagnetic actuator has a single electromagnet, and first and second armatures disposed opposite to the opposite attracting surfaces of the electromagnet, respectively. The first armature actuates a first operating lever for operating the shutter release mechanism of a camera, and the second armature actuates a second operating lever for operating the diaphragm of the camera. The first armature is separated from the attracting surface and the second armature is in contact with the attracting surface while the electromagnet is not energized. When the electromagnet is energized, the first armature is attracted to the attracting surface to actuate the first operating lever for releasing the shutter. When the electromagnet is de-energized, the second armature is separated from the attracting surface to allow the second operating lever which has been detained by the second armature to be turned for controlling the diaphragm. A control circuit decreases the current energizing the electromagnet after the first and second armatures have been attracted to the corresponding attracting surfaces to save power.
Inventors: | Murashima; Nobuharu (Osaka, JP); Kajita; Hideo (Osaka, JP); Hawai; Yasuo (Osaka, JP); Ishimura; Toshihiko (Osaka, JP); Okuno; Akira (Osaka, JP); Tanii; Junichi (Osaka, JP); Seki; Reiji (Osaka, JP) |
Assignee: | Minolta Camera Kabushiki Kaisha (Osaka, JP) |
Appl. No.: | 330450 |
Filed: | March 30, 1989 |
Apr 01, 1988[JP] | 63-78093 | |
Apr 01, 1988[JP] | 63-78094 | |
Apr 11, 1988[JP] | 63-87386 | |
May 11, 1988[JP] | 63-115401 | |
May 11, 1988[JP] | 63-115402 | |
May 11, 1988[JP] | 63-115403 |
Current U.S. Class: | 335/265; 335/281; 396/463 |
Intern'l Class: | H01F 007/08; H01F 003/00; G03B 007/08 |
Field of Search: | 335/265,267,281,282 337/276 354/440 |
2735968 | Feb., 1956 | Bogue et al. | 335/267. |
3343112 | Sep., 1967 | Schulze | 335/276. |
3453572 | Jul., 1969 | Masterson | 335/276. |
3477049 | Nov., 1969 | Kreidler | 335/276. |
4132474 | Jan., 1979 | Ueda et al. | |
4133608 | Jan., 1979 | Tanaka. | |
4160983 | Jul., 1979 | Inagaki et al. | |
4682133 | Jul., 1987 | Kern | 335/265. |
4833435 | May., 1989 | Ohara | 335/265. |
Foreign Patent Documents | |||
58-170 | Jan., 1983 | JP. | |
58-40576 | Sep., 1983 | JP. | |
59-47442 | Nov., 1984 | JP. | |
60-20115 | Feb., 1985 | JP. | |
60-18804 | Jun., 1985 | JP. |